Det Chief Insp Jordan added: "The key to immobilising any mobile phone is to make a note of the unique IMEI number. This can be obtained by dialling *#06#.

"The number is built into the phone and cannot be altered.

"If the phone is lost or stolen, the IMEI number can be given to the network company which will immobilise it so it can no longer be used."

Det Chief Insp Jordan said phone companies should be congratulated for their efforts to combat theft.

"It goes without saying that if the mobile has no value it is no longer attractive to criminals," he said.

West Yorkshire police launched a force-wide campaign in May, texting more than 4,000 mobile phone users across the county with a message reminding them if their mobile is stolen they should contact their network and have it barred, ensuring it never works again.

"Young people are particularly vulnerable to this type of crime," said Det Chief Insp Jordan.

"It is important to keep mobile phones out of sight when they are not being used.

"Don't send text messages or make calls in crowded areas like shopping centres and high streets where they can be snatched out of your hand."

He said the message was also being given directly to criminals in police custody.

"Posters will be displayed in our cell areas and a leaflet will be given to everyone who is arrested to make them realise that stealing mobile phones is no longer profitable and a waste of time," he said.

Since April this year, almost one in five street robberies involved the theft of a mobile phone and 133 phones have been taken during house burglaries.